Cleaning roller for cleaning robots

ABSTRACT

A cleaning roller is mountable to a cleaning robot. The cleaning roller includes a sheath comprising a shell, an outer diameter of the shell tapering from a first end portion of the sheath and a second end portion of the sheath toward a center of the roller. The cleaning roller further includes a core including a central portion interlocked with the sheath to rotationally couple the core to the sheath and inhibit relative translation of the sheath and the core along an axis of rotation. An inner surface of the sheath and an outer surface of the core define an air gap therebetween, the air gap extending from the central portion of the core longitudinally along the axis of rotation toward the first end portion or the second end portion.

TECHNICAL FIELD

This specification relates to cleaning rollers, in particular, forcleaning robots.

BACKGROUND

An autonomous cleaning robot can navigate across a floor surface andavoid obstacles while vacuuming the floor surface and operatingrotatable members carried by the robot to ingest debris from the floorsurface. As the robot moves across the floor surface, the robot canrotate the rotatable members, which engage the debris and guide thedebris toward a vacuum airflow generated by the robot. The rotatablemembers and the vacuum airflow can thereby cooperate to allow the robotto ingest debris.

SUMMARY

In one aspect, a cleaning roller mountable to a cleaning robot isfeatured. The cleaning roller includes a sheath including a shell, and acore extending from a first end portion to a second end portion along anaxis of rotation of the roller. An outer diameter of the shell tapersfrom a first end portion of the sheath and a second end portion of thesheath toward a center of the roller. The first and second end portionsof the core are mountable to the robot for rotating about the axis ofrotation. The core includes a central portion interlocked with thesheath to rotationally couple the core to the sheath and inhibitrelative translation of the sheath and the core along the axis ofrotation. An inner surface of the sheath and an outer surface of thecore define an air gap therebetween, the air gap extending from thecentral portion of the core longitudinally along the axis of rotationtoward the first end portion or the second end portion.

In another aspect, an autonomous cleaning robot includes a body, a driveoperable to move the body across a floor surface, and a cleaningassembly including a cleaning roller rotatable about an axis of rotationof the roller. The cleaning roller includes a sheath including a shell,and a core extending from a first end portion to a second end portionalong the axis of rotation of the roller. An outer diameter of the shelltapers from a first end portion of the sheath and a second end portionof the sheath toward a center of the roller. The core includes a centralportion interlocked with the sheath to rotationally couple the core tothe sheath and inhibit relative translation of the sheath and the corealong the axis of rotation. An inner surface of the sheath and an outersurface of the core define an air gap therebetween, the air gapextending from the central portion of the core longitudinally along theaxis of rotation toward the first end portion or the second end portion.

In some implementations, the cleaning roller further includes a firstcircular member proximate the first end portion of the core andextending radially outward from the outer surface of the core toward theinner surface of the sheath, and a second circular member proximate thesecond end portion of the core and extending radially outward from theouter surface of the core toward the inner surface of the sheath. Thecore can extend along the axis of rotation through centers of the firstand second circular members.

In some cases, the first and second circular members are configured tocontact the inner surface of the sheath to radially support the sheath.In some cases, thicknesses of the first and second circular members arebetween 2.5 and 7.5 mm. In some cases, a distance between the firstcircular member and the center of the roller is between 60 and 100 mm,and a distance between the second circular member and the center of theroller is between 60 and 100 mm. In some cases, the first and secondcircular members each includes an outer ring, an inner ring coupled tothe core, and a plurality of elongate members extending between theouter ring and the inner ring. In some cases, each of the plurality ofelongate members extends outward at a non-zero angle relative to aradial axis.

In some cases, the core includes a first locking member abutting thefirst circular member in a first longitudinal direction and a secondlongitudinal direction to inhibit relative longitudinal translation ofthe core and the first circular member, and a second locking memberabutting the second circular member in the first longitudinal directionand the second longitudinal direction to inhibit relative longitudinaltranslation of the core and the second circular member. In some cases, asurface of the first circular member proximate the inner surface of thesheath and a surface of the second circular member proximate the innersurface of the sheath are sloped toward the center of the roller. Insome cases, a distance between the first circular member and the centerof the roller is between 25% and 45% of a length of the roller and adistance between the second circular member and the center of the rolleris between 25% and 45% of a length of the roller.

In some implementations, the central portion of the core includes one ormore locking members extending radially outward from a shaft portion ofthe core. The sheath can include a locking member extending radiallyinward from the inner surface of the shell. The locking member of thesheath abuts the one or more locking members of the central portion ofthe core in a first longitudinal direction and a second longitudinaldirection. In some cases, the one or more locking members includes asurface facing the second end portion of the core. The surface can forma non-perpendicular angle with the axis of rotation. In some cases, theone or more locking members of the sheath abut the one or more lockingmembers of the central portion of the core in a direction of rotation ofthe roller.

In some implementations, the air gap has a length at least 25% of alength of the cleaning roller.

In some implementations, the sheath includes a vane extending radiallyoutwardly from an outer surface of the shell and following a first pathalong the outer surface of the shell, and a plurality of nubs protrudingradially outwardly from the outer surface of the shell and spaced apartfrom one another along the outer surface of the shell. Each of the nubscan follow a portion of a second path circumferentially offset along theouter surface of the shell from the first path. A first portion of thenubs can extend longitudinally from the first end portion of the sheathtoward the center of the roller along 15% to 35% of a length of theroller, and a second portion of the nubs can extend longitudinally fromthe second end portion of the sheath toward the roller of the sheathalong 15% to 35% of the length of the roller.

In some cases, a height of the vane relative to the axis of rotation isuniform across a length of the roller. Heights of the nubs can beuniform along the portion of the second path relative to the axis ofrotation. The height of the vane can be 0.5 to 1.5 mm greater than theheights of the nubs.

In some implementations, the sheath includes a first vane extendingradially outwardly from an outer surface of the shell and following afirst path along the outer surface of the shell, a second vane extendingradially outwardly from an outer surface of the shell and following asecond path along the outer surface of the shell. The second path can becircumferentially offset along the outer surface of the shell from thefirst path. The sheath can further include a plurality of nubsprotruding radially outwardly from the outer surface of the shell andspaced apart from one another along the outer surface of the shell. Eachof the nubs can follow a portion of a third path circumferentiallyoffset along the outer surface of the shell from the first path and thesecond path. The third path can be positioned along the outer surface ofthe shell between the first path and the second path.

Advantages of the foregoing may include, but are not limited to, thosedescribed below and herein elsewhere. With a roller sheath beinginterlocked with a roller core at a central portion of the core, torqueapplied to the core can be easily transferred to the sheath such thatthe sheath can rotate and draw debris into the robot in response torotation of the core. This interlocking mechanism between the sheath andthe core can use less material than rollers that have sheaths and coresinterlocked across a large portion of the overall length of the roller,e.g., 50% or more of the overall length of the roller.

Furthermore, circular members that radially support the sheath can havea relatively small thickness compared to an overall length of theroller. The circular members can thus provide radial support to thesheath without contributing a significant amount of mass to the overallmass of the roller. Between locations at which the sheath is radiallysupported, the resilience of the sheath enables the sheath to deformradially inward in response to contact with debris and other objects andthen resiliently return to an undeformed state when the debris or otherobjects are no longer contacting the sheath. As a result, the core doesnot need to support the sheath across an entire length of the sheath,thereby reducing the overall amount of material used for supporting thesheath. The decreased overall material used in the roller, e.g., throughuse of the interlocking mechanism and the circular members, can decreasevibrations induced by rotation of the roller and can decrease the riskof lateral deflection of the roller induced by centripetal forces on theroller. This can improve the stability of the roller during rotation ofthe roller while also decreasing the amount of noise generated uponimpact of the roller with objects, e.g., debris or the floor surface.

The roller can further include features that make the roller more easilymanufactured and assembled. For example, locking features such as thelocking members provide coupling mechanisms between the components ofthe roller, e.g., the sheath, the core, and the circular members,without fasteners or adhesives. These locking features can further bepoka-yoke, thereby reducing the risk that the roller is assembled ormanufactured incorrectly.

The details of one or more implementations of the subject matterdescribed in this specification are set forth in the accompanyingdrawings and the description below. Other potential features, aspects,and advantages will become apparent from the description, the drawings,and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional side view of a cleaning robot during acleaning operation.

FIG. 1B is a cross-sectional bottom view of cleaning rollers of therobot taken along the section 1B-1B shown in FIG. 1A.

FIG. 1C is a bottom view of a cleaning head of the robot of FIG. 1Aduring the cleaning operation.

FIGS. 2A and 2B are a bottom view and a bottom perspective explodedview, respectively, of the robot of FIG. 1A.

FIGS. 3A-3D are front perspective, front perspective exploded, front,and front cross-sectional views, respectively, of a cleaning roller.

FIGS. 4A and 4B are front perspective and front views, respectively, ofa core of the cleaning roller of FIG. 3A.

FIGS. 5A and 5B are partial cutaway and front cutaway views,respectively, of a sheath of cleaning roller of FIG. 3A.

FIG. 5C is a stitched image of a cross-sectional side view of the sheathof FIG. 5A along section 5C-5C and a side view of the sheath of FIG. 5A.

FIG. 5D is a front view of a portion of the sheath of FIG. 5A.

FIG. 5E is a side view of the sheath of FIG. 5A.

FIG. 6 is a schematic diagram of the cleaning roller of FIG. 3A.

FIGS. 7A, 8A, and 9A are side views of, and FIGS. 7B, 8B, and 9B arefront views of examples of support members.

FIGS. 10A, 10B, and 10C are perspective, front, and side views of anexample of a cleaning roller.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

Referring to FIG. 1A, a cleaning head 100 for a cleaning robot 102includes rotatable members, e.g., cleaning rollers 104 a, 104 b, thatare positioned to engage debris 106 on a floor surface 10. The robot 102moves about the floor surface 10 while rotating the rollers 104 a, 104 band operating a vacuum assembly 118 to ingest the debris 106 from thefloor surface 10. During the cleaning operation, the rollers 104 a, 104b rotate to lift the debris 106 from the floor surface 10 into the robot102 while the robot 102 moves about the floor surface 10. The rotationof the rollers 104 a, 104 b facilitates movement of the debris 106toward an interior of the robot 102. Outer surfaces of the rollers 104a, 104 b contact and engage the debris 106 and then direct the debris106 toward an interior of the robot 102. The contact between the rollers104 a, 104 b and the debris 106 further agitates the debris 106,enabling the debris 106 to be more easily suctioned into the robot 102.

As shown in FIGS. 1B and 1C, a separation 108 and an air opening 109 aredefined between the roller 104 a and the roller 104 b. The separation108 corresponds to a separation between shells 222 a, 222 b (shown inFIG. 1B) of the rollers 104 a, 104 b. The separation 108 varies alonglengths of the rollers 104 a, 104 b and facilitates movement of thedebris 106 caused by the rollers 104 a, 104 b upward toward the interiorof the robot 102 so that the debris 106 can be ingested by the robot102. Rather than being uniformly separated along the lengths of therollers 104 a, 104 b, the shells 222 a, 222 b are separated by theseparation 108 that varies in width along the lengths of the rollers 104a, 104 b. The air opening 109 enables airflow generated by the vacuumassembly 118 to be generated at locations proximate the rollers 104 a,104 b, e.g., below the rollers 104 a, 104 b proximate the floor surface10 and along the outer surfaces of the rollers 104 a, 104 b. A width ofthe air opening 109 corresponds to the distance between outer diametersof the rollers 104 a, 104 b. The air opening 109 is sized to accommodatedebris 106 moved by the rollers 104 a, 104 b as the rollers 104 a, 104 brotate. The width of the air opening 109 varies as the rollers 104 a,104 b rotate due to changes in geometry of the surface of the rollers104 a, 104 b facing one another.

Referring to FIG. 1B, which shows a longitudinal cross-section of therollers 104 a, 104 b, air gaps 242 a, 242 b, 244 a, 244 b span portionsof interiors of the rollers 104 a, 104 b. The air gaps 242 a, 242 b, 244a, 244 b span portions of the rollers 104 a, 104 b in which sheaths 220a, 220 b of the rollers 104 a, 104 b do not transversally contact orradially contact support structures 226 a, 226 b. The support structures226 a, 226 b are circumferentially surrounded by the sheaths 220 a, 220b and are coaxially aligned with the longitudinal axes 126 a, 126 b ofthe rollers 104 a, 104 b. As the debris 106 is ingested by the roller104 a 104 b, the air gaps 242 a, 242 b, 244 a, 244 b enable outersurfaces of the rollers 104 a, 104 b to inwardly deflect, e.g., toresiliently deflect toward longitudinal axes 126 a, 126 b of the rollers104 a, 104 b. This enables larger pieces of the debris 106 to be moreeasily ingested. In addition, because of the air gaps 242 a, 242 b, 244a, 244 b, the rollers 104 a, 104 b are formed of less material and havesmaller masses as compared to solid rollers without air gaps in theirinteriors. By being formed of less material, the rollers 104 a, 104 bcan be more easily manufactured and, in particular, can be manufacturedwith smaller amounts of runout, e.g., circular, semicircular, or arcuategeometry that is off-center relative to an axis of rotation of therollers 104 a, 104 b due to an error during manufacturing. As a result,the rollers 104 a, 104 b are less prone to vibrating during rotation ascompared to rollers that have greater amounts of runout. Furthermore,the smaller masses of the rollers 104 a, 104 b can reduce centripetalforces on the rollers 104 a, 104 b and thus decrease lateral deflectionsof the rollers 104 a, 104 b during rotation. The air gaps 242, 244 ofthe rollers 104 a, 104 b can therefore improve stability of and decreasenoise generated by the rollers 104 a, 104 b during rotation.

Example Cleaning Robots

The robot 102 is an autonomous cleaning robot that autonomouslytraverses the floor surface 10 while ingesting the debris 106 fromdifferent parts of the floor surface 10. In the example depicted inFIGS. 1A and 2A, the robot 102 includes a body 200 movable across thefloor surface 10. The body 200 includes, in some cases, multipleconnected structures to which movable components of the robot 102 aremounted. For example, the connected structures forming the body 200include an outer housing to cover internal components of the robot 102,a chassis to which drive wheels 210 a, 210 b and the rollers 104 a, 104b are mounted, a bumper mounted to the outer housing, a lid for aninternal cleaning bin of the robot 102, etc.

The body 200 includes a front portion 202 a that has a substantiallyrectangular shape and a rear portion 202 b that has a substantiallysemicircular shape. The front portion 202 a is, for example, a frontone-third to front one-half of the robot 102, and the rear portion 202 bis a rear one-half to two-thirds of the robot 102. As shown in FIG. 2A,the front portion 202 a includes two lateral sides 204 a, 204 b that aresubstantially perpendicular to a front side 206 of the front portion 202a. In some implementations, a width W1 of the robot 102, e.g., adistance between the two lateral sides 204 a, 204 b, is between 20 cmand 60 cm, e.g., between 20 cm and 40 cm, 30 cm and 50 cm, 40 cm and 60cm, etc.

The robot 102 includes a drive system including actuators 208 a, 208 b,e.g., motors, operable with drive wheels 210 a, 210 b. The actuators 208a, 208 b are mounted in the body 200 and are operably connected to thedrive wheels 210 a, 210 b, which are rotatably mounted to the body 200.The drive wheels 210 a, 210 b support the body 200 above the floorsurface 10. The actuators 208 a, 208 b, when driven, rotate the drivewheels 210 a, 210 b to enable the robot 102 to autonomously move acrossthe floor surface 10.

The robot 102 includes a controller 212 that operates the actuators 208a, 208 b to autonomously navigate the robot 102 about the floor surface10 during a cleaning operation. The actuators 208 a, 208 b are operableto drive the robot 102 in a forward drive direction 116 (shown in FIG.1A) and to turn the robot 102. In some implementations, the robot 102includes a caster wheel 211 that supports the body 200 above the floorsurface 10. For example, the caster wheel 211 supports the rear portion202 b of the body 200 above the floor surface 10, and the drive wheels210 a, 210 b support the front portion 202 a of the body 200 above thefloor surface 10.

As shown in FIGS. 1A and 2A, the vacuum assembly 118 is carried withinthe body 200 of the robot 102, e.g., in the rear portion 202 b of thebody 200. Referring to FIG. 2A specifically, the controller 212 operatesthe vacuum assembly 118 to generate an airflow 120 that flows throughthe air opening 109 near the rollers 104 a, 104 b, through the body 200,and out of the body 200. For example, the vacuum assembly 118 includesan impeller that generates the airflow 120 when rotated. The vacuumassembly 118 generates the air flow 120 as the rollers 104 a, 104 brotate to ingest debris 106 into the robot 102. A cleaning bin 122mounted in the body 200 is configured to store the debris 106 ingestedby the robot 102. A filter 123 in the body 200 separates the debris 106from the airflow 120 before the airflow 120 enters the vacuum assembly118 and is exhausted out of the body 200. In this regard, the debris 106is captured in both the cleaning bin 122 and the filter 123 before theairflow 120 is exhausted from the body 200.

As shown in FIG. 2A, the cleaning head 100 and the rollers 104 a, 104 bare positioned in the front portion 202 a of the body 200 between thelateral sides 204 a, 204 b. The rollers 104 a, 104 b are operablyconnected to an actuation mechanism of the robot 102. In particular, therollers 104 a, 104 b are operably connected to an actuation mechanismincluding a drive mechanism connected to an actuator 214 of the robot102 such that torque provided by the actuator 214 can be delivered todrive the rollers 104 a, 104 b. The cleaning head 100 and the rollers104 a, 104 b are positioned forward of the cleaning bin 122, which ispositioned forward of the vacuum assembly 118. In the example of therobot 102 described with respect to FIGS. 2A, 2B, the substantiallyrectangular shape of the front portion 202 a of the body 200 enables therollers 104 a, 104 b to be longer than cleaning rollers for cleaningrobots with, for example, a circularly shaped body.

The rollers 104 a, 104 b are mounted to a housing 124 (also shown inFIGS. 1A and 1C) of the cleaning head 100 and mounted, e.g., indirectlyor directly, to the body 200 of the robot 102. In particular, therollers 104 a, 104 b are mounted to an underside of the front portion202 a of the body 200 so that the rollers 104 a, 104 b engage debris 106on the floor surface 10 during the cleaning operation when the undersideof the front portion 202 a faces the floor surface 10. In someimplementations, the housing 124 of the cleaning head 100 is mounted tothe body 200 of the robot 102. In this regard, the rollers 104 a, 104 bare also mounted to the body 200 of the robot 102, e.g., indirectlymounted to the body 200 through the housing 124. Alternatively oradditionally, the cleaning head 100 is a removable assembly of the robot102 in which the housing 124 with the rollers 104 a, 104 b mountedtherein is removably mounted to the body 200 of the robot 102. Thehousing 124 and the rollers 104 a, 104 b are removable from the body 200as a unit so that the cleaning head 100 is easily interchangeable with areplacement cleaning head.

In some implementations, rather than being removably mounted to the body200, the housing 124 of the cleaning head 100 is not a componentseparate from the body 200, but rather, corresponds to an integralportion of the body 200 of the robot 102. The rollers 104 a, 104 b aremounted to the body 200 of the robot 102, e.g., directly mounted to theintegral portion of the body 200. The rollers 104 a, 104 b are eachindependently removable from the housing 124 of the cleaning head 100and/or from the body 200 of the robot 102 so that the rollers 104 a, 104b can be easily cleaned or be replaced with replacement rollers. Asdescribed herein, the rollers 104 a, 104 b can include collection wellsfor filament debris that can be easily accessed and cleaned by a userwhen the rollers 104 a, 104 b are dismounted from the housing 124.

The rollers 104 a, 104 b are rotatable relative to the housing 124 ofthe cleaning head 100 and relative to the body 200 of the robot 102. Asshown in FIGS. 1A, 1C, and 2A, the rollers 104 a, 104 b are rotatableabout longitudinal axes 126 a, 126 b parallel to the floor surface 10.The axes 126 a, 126 b are parallel to one another and correspond tolongitudinal axes of the rollers 104 a, 104 b, respectively. In somecases, the longitudinal axes 126 a, 126 b are perpendicular to theforward drive direction 116 of the robot 102. Referring to FIGS. 1B and1C, centers 114 a, 114 b of the rollers 104 a, 104 b are positionedalong the longitudinal axes 126 a, 126 b, respectively, and correspondto midpoints of lengths of the rollers 104 a, 104 b. The centers 114 a,114 b, in this regard, are positioned along the axes of rotation of therollers 104 a, 104 b. A length L1 (shown in FIG. 1B) of one or both ofthe rollers 104 a, 104 b is between, for example, 10 cm and 50 cm, e.g.,between 10 cm and 30 cm, 20 cm and 40 cm, 30 cm and 50 cm, 20 cm and 30cm, 22 cm and 26 cm, 23 cm and 25 cm, or about 24 cm. The length L1 is,for example, between 70% and 90% of an overall width W1 of the robot102, e.g., between 70% and 80%, 75% and 85%, and 80% and 90%, etc., ofthe overall width W1 of the robot 102.

Referring to the exploded view of the cleaning head 100 shown in FIG.2B, each of the rollers 104 a, 104 b includes the sheath 220 a, 220 band the support structure 226 a, 226 b. The sheaths 220 a, 220 b eachincludes a shell 222 a, 222 b and vanes 224 a, 224 b (also shown in FIG.1C). The support structures 226 a, 226 b each includes a core 228 a, 228b, a first support member 230 a, 230 b, and a second support member 232a, 232 b.

In some implementations, the sheath 220 a, 220 b is a single moldedpiece formed from one or more elastomeric materials. For example, therollers 104 a, 104 b are elastomeric rollers featuring a pattern ofchevron-shaped vanes 224 a, 224 b distributed along an exterior surfaceof the rollers 104 a, 104 b. The vanes 224 a, 224 b of at least one ofthe rollers 104 a, 104 b, e.g., the roller 104 a, make contact with thefloor surface 10 along the length of the rollers 104 a, 104 b andexperience a consistently applied friction force during rotation that isnot present with brushes having pliable bristles. The high surfacefriction of the sheath 220 a, 220 b enables the sheath 220 a, 220 b toengage the debris 106 and guide the debris 106 toward the interior ofthe robot 102, e.g., toward an air conduit 128 (shown in FIG. 1A) withinthe robot 102.

Furthermore, like cleaning rollers having distinct bristles extendingradially from a rod member, the rollers 104 a, 104 b have the vanes 224a, 224 b that extend radially outward. The vanes 224 a, 224 b, however,also extend continuously along the outer surface of the rollers 104 a,104 b in longitudinal directions. The vanes 224 a, 224 b extend alongcircumferential directions along the outer surface of the rollers 104 a,104 b, thereby defining V-shaped paths along the outer surface of therollers 104 a, 104 b as described herein. Other suitable configurations,however, are also contemplated. For example, in some implementations, atleast one of the rear and front rollers 104 a, 104 b may includebristles and/or elongated pliable flaps for agitating the floor surfacein addition or as an alternative to the vanes 224 a, 224 b.

For each of the rollers 104 a, 104 b, the shell 222 a, 222 b and itscorresponding vanes 224 a, 224 b are part of the single molded piece.The shell 222 a, 222 b is radially supported by the support structure226 a, 226 b at multiple discrete locations along the length of theroller 104 a, 104 b and is unsupported between the multiple discretelocations. For example, as described herein, the shell 222 a, 222 b issupported at a central portion 233 a, 233 b of the core 228 a, 228 b andby the first support members 230 a, 230 b and the second support members232 a, 232 b. The first support members 230 a, 230 b and the secondsupport members 232 a, 232 b are members having circular outerperimeters that contact encircling segments of an inner surface of thesheath 220 a, 220 b. The support members 230 a, 230 b, 232 a, 232 bthereby radially or transversally support the sheath 220 a, e.g.,inhibit deflection of the sheath 220 a toward the longitudinal axis 126a, 126 b (shown in FIGS. 1B and 1C) in response to forces transverse tothe longitudinal axis 126 a, 126 b. Where supported by the supportmembers 230 a, 230 b, 232 a, 232 b or the central portion 233 a, 233 bof the core 228 a, 228 b, the sheath 220 a, 220 b is inhibited fromdeflecting radially inward, e.g., in response to contact with objectssuch as the floor surface 10 or debris collected from the floor surface10. Furthermore, the support members 230 a, 230 b, 232 a, 232 b and thecentral portion 233 a, 233 b of the core 228 a, 228 b maintain outercircular shapes of the shell 222 a, 222 b.

Between each support member 230 a, 232 a, 230 b, 232 b and the centralportion 233 a, 233 b of the core 228 a, 228 b, the sheath 220 a, 220 bis unsupported. For example, the support structure 226 a, 226 b does notcontact the sheath 220 a, 220 b between the support members 230 a, 232a, 230 b, 232 b and the central portion 233 a, 233 b of the core 228 a,228 b. As described herein, the air gaps 242 a, 242 b, 244 a, 244 b spanthese unsupported portions and provide space for the sheath 220 a, 220 bto deflect radially inwardly, e.g., to deflect toward the longitudinalaxis 126 a, 126 b.

The rollers 104 a, 104 b further include rod members 234 a, 234 brotatably coupled to mounting devices 218 a, 218 b and rotationallycoupled to the support structures 226 a, 226 b. The mounting devices 218a, 218 b are mounted to the robot body 200, the cleaning head housing124, or both so that the mounting devices 218 a, 218 b are rotationallyfixed to the robot body 200, the cleaning head housing 124, or both. Inthis regard, the rod members 234 a, 234 b and the core 228 a, 228 brotate relative to the mounting devices 218 a, 218 b as the rollers 104a, 104 b are driven to rotate.

The rod members 234 a, 234 b are insert-molded components separate fromthe support structures 226 a, 226 b. For example, the rod members 234 a,234 b are formed from metal and are rotatably coupled to the mountingdevices 218 a, 218 b, which in turn are rotationally fixed to the body200 of the robot 102 and the housing 124 of the cleaning head 100.Alternatively, the rod members 234 a, 234 b are integrally formed withthe support structures 226 a, 226 b.

The rollers 104 a, 104 b further include elongate portions 236 a, 236 boperably connected to an actuator 214 (shown schematically in FIG. 2A)of the robot 102 when the rollers 104 a, 104 b are mounted to the body200 of the robot 102 or the housing 124 of the cleaning head 100. Theelongate portions 236 a, 236 b are rotationally fixed to engagementportions (not shown) of the actuation system of the robot 102, therebyrotationally coupling the rollers 104 a, 104 b to the actuator 214. Theelongate portions 236 a, 236 b also rotatably mount the rollers 104 a,104 b to the body of the robot 102 and the housing 124 of the cleaninghead 100 such that the rollers 104 a, 104 b rotate relative to the body200 and the housing 124 during the cleaning operation.

As shown in FIG. 1C, the roller 104 a and the roller 104 b are spacedfrom another such that the longitudinal axis 126 a of the roller 104 aand the longitudinal axis 126 b of the roller 104 b define a spacing S1.The spacing S1 is, for example, between 2 and 6 cm, e.g., between 2 and4 cm, 4 and 6 cm, etc.

The roller 104 a and the roller 104 b are mounted such that the shell222 a of the roller 104 a and the shell 222 b of the roller 104 b definethe separation 108, and the vanes 224 a, 224 b define the air opening109. The separation 108 and the air opening 109 both extend from a firstouter end portion 110 a of the roller 104 a to a second outer endportion 112 a of the roller 104 a, or from a first outer end portion 110b of the roller 104 b to a second outer end portion 112 b of the roller104 b. As described herein, the separation 108 corresponds to a distancebetween the rollers 104 a, 104 b absent vanes 224 a, 224 b (and absentnubs as present in some implementations described herein) on the rollers104 a, 104 b, while the air opening 109 has a width corresponding to thedistance between the rollers 104 a, 104 b including the vanes 224 a, 224b on the rollers 104 a, 104 b. While the air opening 109 can vary inwidth during rotation of the rollers 104 a, 104 b, the separation 108has a constant width during rotation of the rollers 104 a, 104 b.

The separation 108 decreases in width in directions toward the endportions 110 a, 112 a of the roller 104 a. Such a configuration of theseparation 108 can improve debris pickup capabilities of the rollers 104a, 104 b, e.g., the rear roller 104 a and the front roller 104 b whilereducing likelihood that filament debris picked up by the rollers 104 a,104 b impedes operations of the rollers 104 a, 104 b. The separation 108is between the shell 222 a of the rear roller 104 a and the shell 222 bof the front roller 104 b and extends longitudinally along the shells222 a, 222 b. In particular, the outer surface of the shell 222 b of thefront roller 104 b and the outer surface of the shell 222 a of the rearroller 104 a are separated by the separation 108, which varies in widthalong the longitudinal axes 126 a, 126 b of the rollers 104 a, 104 b.The separation 108 tapers toward the center 114 a of the roller 104 a,e.g., towards a plane passing through centers of the both of the rollers104 a, 104 b and perpendicular to the longitudinal axes 126 a, 126 b.The separation 108 increases in size toward the center 114 a of thelength L1 of the roller 104 a.

The separation 108 is measured as a width between the outer surface ofthe shell 222 a of the rear roller 104 a and the outer surface of theshell 222 b of the front roller 104 b. In some cases, the width of theseparation 108 is measured as the closest distance between the shell 222a and the shell 222 b at various points along the longitudinal axis 126a and along a plane extending through both of the longitudinal axes 126a, 126 b. In this regard, the width varies such that the distance S3between the rollers 104 a, 104 b at their centers is greater than thedistance S2 at their ends.

Referring to inset 132 a in FIG. 1C, a length S2 of the separation 108proximate the first end portion 110 a of the roller 104 a is between 2and 10 mm, e.g., between 2 mm and 6 mm, 4 mm and 8 mm, 6 mm and 10 mm,etc. The length S2 of the separation 108, for example, corresponds to aminimum length of the separation 108 along the length L1 of the roller104 a.

Referring to inset 132 b in FIG. 1A, a length S3 of the separation 108proximate the center 114 a of the roller 104 a is between, for example,5 mm and 30 mm, e.g., between 5 mm and 20 mm, 10 mm and 25 mm, or 15 mmand 30 mm. The length S3 is, for example, 3 to 15 times greater than thelength S2, e.g., 3 to 5 times, 5 to 10 times, or 10 to 15 times greaterthan the length S2. The length S3 of the separation 108, for example,corresponds to a maximum length of the separation 108 along the lengthL1 of the roller 104 a. In some cases, the separation 108 linearlyincreases from the center 114 a of the roller 104 a toward the endportions 110 a, 110 b.

The air opening 109 between the rollers 104 a, 104 b is defined as anopening having a width corresponding to the distance between free tipsof the vanes 224 a, 224 b (shown in the inset 132 b of FIG. 1C) onopposing rollers 104 a, 104 b. In some examples, the distance variesdepending on how the vanes 224 a, 224 b align during rotation. The airopening 109 between the sheaths 220 a, 220 b of the rollers 104 a, 104 bvaries along the longitudinal axes 126 a, 126 b of the rollers 104 a,104 b. In particular, the width of the air opening 109 varies in sizedepending on relative positions of the vanes 224 a, 224 b of the rollers104 a, 104 b. The width of the air opening 109 is defined by thedistance between the outer circumferences of the sheath 220 a, 220 b,e.g., defined by the vanes 224 a, 224 b, when the vanes 224 a, 224 bface one another during rotation of the rollers 104 a, 104 b. The widthof the air opening 109 is defined by the distance between the outercircumferences of the shells 222 a, 222 b when the vanes 224 a, 224 b ofboth rollers 104 a, 104 b do not face the other roller. In this regard,while the outer circumference of the rollers 104 a, 104 b is consistentalong the lengths of the rollers 104 a, 104 b as described herein, theair opening 109 between the rollers 104 a, 104 b varies in width as therollers 104 a, 104 b rotate. In particular, while the separation 108 hasa constant length during rotation of the opposing rollers 104 a, 104 b,the distance defining the air opening 109 changes during the rotation ofthe rollers 104 a, 104 b due to relative motion of the vanes 224 a, 224b of the rollers 104 a, 104 b. The air opening 109 varies in width froma minimum width of 1 mm to 10 mm when the vanes 224 a, 224 b face oneanother to a maximum width of 5 mm to 30 mm when the vanes 224 a, 224 bare not aligned. The maximum width corresponds to, for example, thelength S3 of the separation 108 at the centers of the rollers 104 a, 104b, and the minimum width corresponds to the length of this separation108 minus the heights of the vanes 224 a, 224 b at the centers of therollers 104 a, 104 b.

Referring to FIG. 2A, in some implementations, to sweep debris 106toward the rollers 104 a, 104 b, the robot 102 includes a brush 233 thatrotates about a non-horizontal axis, e.g., an axis forming an anglebetween 75 degrees and 90 degrees with the floor surface 10. Thenon-horizontal axis, for example, forms an angle between 75 degrees and90 degrees with the longitudinal axes 126 a, 126 b of the rollers 104 a,104 b. The robot 102 includes an actuator 235 operably connected to thebrush 233. The brush 233 extends beyond a perimeter of the body 200 suchthat the brush 233 is capable of engaging debris 106 on portions of thefloor surface 10 that the rollers 104 a, 104 b typically cannot reach.

During the cleaning operation shown in FIG. 1A, as the controller 212operates the actuators 208 a, 208 b to navigate the robot 102 across thefloor surface 10, if the brush 233 is present, the controller 212operates the actuator 235 to rotate the brush 233 about thenon-horizontal axis to engage debris 106 that the rollers 104 a, 104 bcannot reach. In particular, the brush 233 is capable of engaging debris106 near walls of the environment and brushing the debris 106 toward therollers 104 a, 104 b. The brush 233 sweeps the debris 106 toward therollers 104 a, 104 b so that the debris 106 can be ingested through theseparation 108 between the rollers 104 a, 104 b.

The controller 212 operates the actuator 214 to rotate the rollers 104a, 104 b about the axes 126 a, 126 b. The rollers 104 a, 104 b, whenrotated, engage the debris 106 on the floor surface 10 and move thedebris 106 toward the air conduit 128. As shown in FIG. 1A, the rollers104 a, 104 b, for example, counter rotate relative to one another tocooperate in moving debris 106 through the separation 108 and toward theair conduit 128, e.g., the roller 104 a rotates in a clockwise direction130 a while the roller 104 b rotates in a counterclockwise direction 130b.

The controller 212 also operates the vacuum assembly 118 to generate theairflow 120. The vacuum assembly 118 is operated to generate the airflow120 through the separation 108 such that the airflow 120 can move thedebris 106 retrieved by the rollers 104 a, 104 b. The airflow 120carries the debris 106 into the cleaning bin 122 that collects thedebris 106 delivered by the airflow 120. In this regard, both the vacuumassembly 118 and the rollers 104 a, 104 b facilitate ingestion of thedebris 106 from the floor surface 10. The air conduit 128 receives theairflow 120 containing the debris 106 and guides the airflow 120 intothe cleaning bin 122. The debris 106 is deposited in the cleaning bin122. During rotation of the rollers 104 a, 104 b, the rollers 104 a, 104b apply a force to the floor surface 10 to agitate any debris on thefloor surface 10. The agitation of the debris 106 can cause the debris106 to be dislodged from the floor surface 10 so that the rollers 104 a,104 b can more contact the debris 106 and so that the airflow 120generated by the vacuum assembly 118 can more easily carry the debris106 toward the interior of the robot 102. As described herein, thedeflectability of the shells 222 a, 222 b of the rollers 104 a, 104 benable the rollers 104 a, 104 b to deflect in response to larger piecesof debris, thereby enabling debris to be more easily ingested into therobot 102.

Example Cleaning Rollers

The example of the rollers 104 a, 104 b described with respect to FIG.2B can include additional configurations as described with respect toFIGS. 3A-10B. FIGS. 3A and 3B show an example of a roller 300 includingan outer sheath 302 and an internal support structure 304. The roller300, for example, corresponds to the rear roller 104 a described withrespect to FIGS. 1A, 1B, 2A, and 2B. The sheath 302 and the supportstructure 304 are similar to the sheath 220 a and the support structure226 a of the rear roller 104 a. As shown in FIG. 3C, an overall lengthof the roller 300 is similar to the overall length described withrespect to the rollers 104 a, 104 b. For example, the roller 300 has alength L1. Like the roller 104 a, the roller 300 can be mounted to therobot 102 and can be part of the cleaning head 100.

Referring to FIG. 3B, the support structure 304 includes an elongatecore 306 having a first outer end portion 308 and a second outer endportion 310. Referring to FIGS. 4A and 4B, the core 306 extends from thefirst end portion 308 to the second end portion 310 along a longitudinalaxis 312, e.g., the longitudinal axis 126 a about which the roller 104 ais rotated.

A shaft portion 314 of the core 306 extends from the first end portion308 to the second end portion 310 and has an outer diameter D1 (shown inFIG. 4B) between 5 mm and 15 mm, e.g., between 5 and 10 mm, 7.5 mm and12.5 mm, or 10 mm and 15 mm. At least a portion of an outer surface ofthe shaft portion 314 between the first end portion 308 and the secondend portion 310 is a substantially cylindrical portion of the core 306.As described herein, features are arranged circumferentially about thisportion of the outer surface of the shaft portion 314 to enable the core306 to be interlocked with the sheath 302.

The first end portion 308 and the second end portion 310 of the core 306are configured to be mounted to a cleaning robot, e.g., the robot 102,to enable the roller 300 to be rotated relative to the body 200 of therobot 102 about the longitudinal axis 312. The second end portion 310 isan elongate member engageable with an actuation system of the robot 102,e.g., so that the actuator 214 of the robot 102 can be used to drive theroller 300. The second end portion 310 has a non-circular cross-sectionto mate with an engagement portion of the drive mechanism driven by theactuator 214 of the robot 102. For example, the cross-section of thesecond end portion 310 has a prismatic shape having a square,rectangular, hexagonal, pentagonal, another polygonal cross-sectionalshape, a Reuleaux polygonal cross-sectional shape, or other non-circularcross-sectional shape. The second end portion 310 is driven by theactuator of the robot 102 such that the core 306 rotates relative to thebody 200 of the robot 102 and the housing 124 of the cleaning head 100.In particular, the core 306 rotationally couples the roller 300 to theactuator 214 of the robot 102. As described herein, the sheath 302 isrotationally coupled to the core 306 such that the sheath 302 is rotatedrelative to the floor surface 10 in response to rotation of the core306. The sheath 302, which defines the outer surface of the roller 300,contacts debris on the floor surface 10 and rotates to cause the debristo be drawn into the robot 102.

Referring back to FIGS. 3B and 3C, a mounting device 316 (similar to themounting device 218 a) is on the first end portion 308 of the core 306.The mounting device 316 is rotatably coupled to the first end portion308 of the core 306. For example, the first end portion 308 of the core306 includes a rod member 318 (shown in FIG. 3B and, e.g., similar tothe rod member 234 a) that is rotatably coupled to the mounting device316. The core 306 and the rod member 318 are affixed to one another, insome implementations, through an insert molding process during which thecore 306 is bonded to the rod member 318. During rotation of the roller300, the mounting device 316 is rotationally fixed to the body 200 ofthe robot 102 or the housing 124 of the cleaning head 100, and the rodmember 318 rotates relative to the mounting device 316. The mountingdevice 316 functions as a bearing surface to enable the core 306 and therod member 318 to rotate about its longitudinal axis 312 with relativelysmall frictional forces caused by contact between the rod member 318 andthe mounting device 316.

The core 306 is rotationally coupled to the sheath 302 so that rotationof the core 306 results in rotation of the sheath 302. Referring toFIGS. 3B and 3D, the core 306 is rotationally coupled to the sheath 302at a central portion 320 of the core 306. The central portion 320includes features that transfer torque from the core 306 to the sheath302. The central portion 320 is interlocked with the sheath 302 torotationally couple the core 306 to the sheath 302.

In some implementations, the central portion 320 includes one or morelocking members arranged around the shaft portion 314 of the core 306.Referring to the inset 330 a of FIG. 4A and to FIG. 4B, locking members322 are protrusions extending radially outward from the shaft portion314 of the core 306. Outer diameters D2 (shown in FIG. 4B) of thelocking members 322 correspond to twice the distance between anoutermost point of a locking member 322 and the longitudinal axis 312and are between 10 and 20 mm, e.g., between 10 mm and 15 mm, 12.5 mm and17.5 mm, between 15 mm and 20 mm. For example, the outer diameters D2are 30% to 60% greater than the outer diameter D1 of the shaft portion314, e.g., between 35% and 55% or 40% and 50% greater than the outerdiameter D1. As shown in FIG. 4B, the locking members 322 extendlongitudinally along the shaft portion 314, having a length L2 between10 mm and 30 mm, e.g., between 10 mm and 20 mm, 15 mm and 25 mm, or 20mm and 30 mm. For example, the length L2 is between 2.5% and 15% of thelength L1 of the roller 300, e.g., between 1.5% and 7.5%, 5% and 10%,7.5% and 12.5%, or 10% and 15% of the length L1 of the roller 300.

Referring to the inset 331 of FIG. 5A, the locking members 322 of thecore 306 abut corresponding locking members 324 of the sheath 302. Thelocking members 324 of the sheath 302 extend radially inwardly from aninner surface of a shell 350 of the sheath 302 toward the core 306. Acentral portion 323 of the sheath 302 includes the locking members 324.These locking members 324 allow the central portion 323 of the sheath302 to interlock with the central portion 320 of the core 306. Thelocking members 324 of the sheath 302 interlock with the locking members322 of the core 306 such that the locking members 322 of the core 306are positioned circumferentially between adjacent locking members 324 ofthe sheath 302. The locking members 322 and the locking members 324 abutone another in a circumferential direction, e.g., in a direction ofrotation of the roller 300, thereby rotationally coupling the core 306to the sheath 302. Similarly, the locking members 324 of the sheath 302are positioned circumferentially between adjacent locking members 322 ofthe core 306. In this regard, the lengths L2 of the locking members 322correspond to lengths of circumferential engagement between the lockingmembers 322 and the locking members 324.

Referring to FIG. 5C, the locking members 324 of the sheath 302 haveinner diameters D3, e.g., the distance between an innermost point of alocking member 324 and the longitudinal axis 312, shorter than the outerdiameters D2 of the locking members 322 of the core 306. For example,the diameters D2 are between 5 mm and 15 mm, e.g., between 5 and 10 mm,7.5 mm and 12.5 mm, or 10 mm and 15 mm. As shown in FIG. 5B, the lockingmembers 324 extend longitudinally along the shell 350, having a lengthL3 between 5 mm and 25 mm, e.g., between 5 mm and 15 mm, 10 mm and 20mm, or 15 mm and 25 mm. For example, the length L3 is between 2.5% and15% of the length L1 of the roller 300, e.g., between 2.5% and 7.5%, 5%and 10%, 7.5% and 12.5%, or 10% and 15% of the length L1 of the roller300.

In addition to having features to rotationally couple the core 306 tothe sheath 302, the support structure 304 includes features to radiallysupport the sheath 302. For example, larger pieces of debris on thefloor surface 10 may cause the sheath 302 to deform inwardly, and theradial support features can limit the amount of deformation at one ormore locations along the length of the sheath 302. The radial supportfeatures inhibit radially inward deformation of the sheath 302 atmultiple discrete locations along the length of the sheath 302. In theexample depicted in FIG. 3D, the radial support features provide supportat three distinct and separate locations along the length of the sheath302.

For example, the radial support features of the support structure 304include one or more portions of the core 306. The central portion 320 ofthe core 306 abuts the sheath 302 in a radial direction at a center 325of the roller 300. In some implementations, outer tips of the lockingmembers 322 of the core 304 abut the inner surface of the sheath 302 atthe center 325 of the roller 300.

In addition, referring to FIGS. 3B and 3D, the radial support featuresof the support structure 304 include support members 326 a, 326 bmounted to the core 306. The support members 326 a, 326 b are discsformed of a deformable material, e.g., an elastomeric or rubbermaterial. The support members 326 a, 326 b radially support portions ofthe sheath 302 to maintain a round or substantially circular shape ofcross-sections of the shell 350 the sheath 302.

As shown in FIG. 3D, the support member 326 a is proximate or on thefirst end portion 308 of the core 306, and the support member 326 b isproximate or on the second end portion 310 of the core 306. The supportmembers 326 a, 326 b are mounted to the core 306 through a press fit onan outer surface of the core 306. The support members 326 a, 326 b areeach positioned proximate opposite longitudinal ends of the sheath 302at a distance L4 from the center 325 of the roller 300. The distance L4is between 60 mm and 100 mm, e.g., between 60 mm and 80 mm, between 60mm and 70 mm, between 70 mm and 80 mm, between 80 mm and 100 mm, between80 mm and 90 mm, 85 mm and 95 mm, or 90 mm and 100 mm. In someimplementations, the distance L4 is between 30% and 45% of the overalllength L1 of the roller 300, e.g., between 32.5% and 42.5% or 35% and40% of the overall length L1 of the roller 300. The first and secondsupport members 326 a, 326 b are each positioned at a distance L5 fromfirst and second end portions 348 a, 348 b of the sheath 302,respectively. The distance L5 is between 20 mm and 40 mm, e.g., between20 mm and 30 mm, 25 mm and 35 mm, or 30 mm and 40 mm. For example, thedistance L5 is between 5% and 20% of the overall length L1 of the roller300, e.g., between 5% and 15% or 10% and 20% of the length L1 of theroller 300.

The support members 326 a, 326 b extend radially outward from the outersurface of the core 306, e.g., the outer surface of the shaft portion314, to proximate an inner surface of the sheath 302. The supportmembers 326 a, 326 b contact or are configured to contact the innersurface of the sheath 302 when the sheath 302 inwardly deforms towardthe longitudinal axis 312. The support members 326 a, 326 b radiallysupport the sheath 302 to inhibit radially inward deformation of thesheath 302 beyond a certain amount at locations along the sheath 302proximate the support members 326 a, 326 b.

Outer surfaces 328 a, 328 b of the support members 326 a, 326 b have ashape tracking a shape of the inner surface of the sheath 302. In thisregard, the outer surfaces 328 a, 328 b are substantially circular andmaintain circular cross-sectional shapes of the inner surface of thesheath 302 at the locations of the support members 326 a, 326 b. Thelongitudinal axis 312 is coincident with centers of the circular shapesdefined by the outer surfaces 328 a, 328 b, e.g., coincident withcentral axes of the support members 326 a, 326 b. The outer surfaces 328a, 328 b contact the inner surface of the sheath 302 to radially supportthe sheath 302.

The support members 326 a, 326 b are disc-shaped members with diametersmatching diameters of the inner surface of the sheath 302 at thelongitudinal locations of the support members 326 a, 326 b. ThicknessesT1 of the support members 326 a, 326 b, e.g., widths of the supportmembers 326 a, 326 b along the longitudinal axis 312, are between 2.5 mmand 7.5 mm, e.g., between 3.5 mm and 6.5 mm, 4 mm and 6 mm, or 4.5 mmand 5.5 mm. For example, the thicknesses T1 are 0.5% to 3% of the lengthL1 of the roller 300, e.g., 0.5% to 2%, 1% to 2.5%, or 1.5% to 3% of thelength L1 of the roller 300. In some implementations, the outer surfaces328 a, 328 b of the support members 326 a, 326 b are sloped toward thecenter 325 of the roller 300 to match with the taper of the outerdiameter of the shell 350 of the sheath 302 described herein.

The core 306 also includes features to maintain relative positions ofthe sheath 302 and the core 306 along the longitudinal axis 312 andrelative positions of the support members 326 a, 326 b and the core 306along the longitudinal axis 312. For example, the core 306 includes oneor more locking members that abut the sheath 302 to inhibit movement ofthe sheath 302 in a first longitudinal direction 312 a along thelongitudinal axis 312, and one or more locking members that abut thesheath 302 to inhibit movement of the sheath 302 in a second oppositelongitudinal direction 312 b along the longitudinal axis 312.

Referring to the inset 330 a shown in FIG. 4A, a locking member 332 onthe core 306 is positioned in the central portion 320 of the core 306.The locking member 332 extends radially outward from the shaft portion314. The locking member 332 abuts the sheath 302, e.g., abuts thelocking members 324 of the sheath 302, to inhibit movement of the sheath302 relative to the core 306 in the second direction 312 b along thelongitudinal axis 312. The locking member 332 extends radially outwardfrom the shaft portion 314 of the core 306. In some implementations, thelocking member 332 is a continuous ring of material positioned aroundthe shaft portion 314.

Locking members 334 positioned in the central portion 320 of the core306 extend radially outward from the shaft portion 314. The lockingmembers 334 abut the sheath 302, e.g., abuts the locking members 324 ofthe sheath 302, to inhibit movement of the sheath 302 in the firstdirection 312 a along the longitudinal axis 312 relative to the core306, the first direction 312 a being opposite the second direction 312 bin which movement of the sheath 302 is inhibited by the locking member332. As shown in the inset 330 a in FIG. 4A, the locking members 334each includes an abutment surface 334 a that contacts a different one ofthe locking members 324 of the sheath 302. The abutment surface 334 afaces the second end portion 310 of the core 306. The locking members334 also each includes a sloped surface 334 b, e.g., sloped toward thecenter 325 of the roller 300. The sloped surface 334 b faces the firstend portion 308 of the core 306. The sloped surface 334 b can improvemanufacturability of the roller 300 by enabling the sheath 302 and, inparticular, the locking members 324 of the sheath 302, to be easily slidover the locking members 334 and then into contact with the lockingmember 332 during assembly of the roller 300.

The locking member 332 and the locking members 334 cooperate to definethe longitudinal position of the sheath 302 over the core 306. When thesheath 302 is positioned over the core 306, the abutment surfaces 334 aof the locking members 334 contact first longitudinal ends 324 a, andthe locking member 332 contacts second longitudinal ends 324 b (shown inFIG. 5B) of the locking members 324 of the sheath 302 (shown in FIG.5B).

The features that maintain the relative positions of the support members326 a, 326 b and the core 306 along the longitudinal axis 312 includeone or more locking members that abut the support members 326 a, 326 bto inhibit movement of the support members 326 a, 326 b in the firstdirection 312 a along the longitudinal axis 312, and one or more lockingmembers that abut the support members 326 a, 326 b to inhibit movementof the support members 326 a, 326 b in the second direction 312 b alongthe longitudinal axis 312. Referring to the inset 330 b shown in FIG.4A, locking members 336 (only one shown in FIG. 4A) on the core 306extend radially outward from the shaft portion 314. The locking members336 abut the support member 326 a to inhibit movement of the supportmember 326 a relative to the core 306 in the second direction 312 b. Inparticular, abutment surfaces 336 a of the locking members 336 abut thesupport member 326 a to inhibit movement of the support member 326 a inthe second direction 312 b. The abutment surfaces 336 a face the firstend portion 308 of the core 306. Sloped surfaces 336 b of the lockingmembers 336, e.g., sloped toward the center 325 of the roller 300,enable the support member 326 a to easily slide over the locking members336 to position the support member 326 a between the locking members 336and a locking member 338. The sloped surfaces 336 b face the second endportion 310 of the core 306. In this regard, during assembly, thesupport member 326 a is slid over the second end portion 310 of the core306, past the sloped surfaces 336 b, and into the region between thelocking members 336 and the locking member 338.

The locking member 338 on the core 306 extends radially outward from theshaft portion 314. The locking member 338 abuts the support member 326 ato inhibit movement of the support member 326 a relative to the core 306in the second direction 312 b. In some implementations, the lockingmember 338 is a continuous ring of material positioned around the shaftportion 314.

The locking members 336 and the locking member 338 cooperate to definethe longitudinal position of the support member 326 a over the core 306.When the support member 326 a is positioned over the core 306, thelocking member 332 contacts first longitudinal ends of the supportmember 326 a, and the abutment surfaces 334 a of the locking members 334contact second opposite longitudinal ends of the support member 326 a.

Referring to the inset 330 c shown in FIG. 4A, locking members 340 andlocking members 342 on the core 306 abut the support member 326 b toinhibit movement of the support member 326 a relative to the core 306 inthe second direction 312 b and the first direction 312 a, respectively.The locking members 340, their abutment surfaces 340 a, and their slopedsurfaces 340 b are similar to the locking members 336, their abutmentsurfaces 336 a, and their sloped surfaces 336 b to enable the supportmember 326 b to be easily slid over the locking members 340 and intoabutment with the locking member 342. The abutment surfaces 340 a differfrom the abutment surfaces 336 a in that the abutment surfaces 340 aface the second end portion 310 of the core 306, and the sloped surfaces340 b differ from the sloped surfaces 336 b in that the sloped surfaces340 b face the first end portion 308 of the core 306. In this regard,the support member 326 b is slid over the first end portion 308 of thecore 306 to position the support member 326 b in the region between thelocking members 340 and the locking members 342.

In some implementations, the locking members 342 differs from thelocking member 338 in that the locking members 342, rather than beingformed from a continuous ring of material protruding from the shaftportion 314, are distinct protrusions extending from the shaft portion314. The circumferential spacing between the locking members 342 and thelocking members 340 enables the sheath 302 with its locking members 324to be easily slid past the locking members 340, 342 in the firstdirection 312 a during assembly of the roller 300.

The locking members 332, 334, 336, 338, 340, 342 are each positionedaround the shaft portion 314 and can each be integrally molded to thecore 306 such that the shaft portion 314 and the locking members 332,334, 336, 338, 340, 342 form a single component, e.g., a single plasticcomponent. For positioning the sheath 302 and the support members 326 a,326 b over the core 306, the locking members 332, 334, 336, 338, 340,342 can have similar diameters D4 shown in FIG. 4B. In someimplementations, the outer diameter D4 is between 10 and 20 mm, e.g.,between 10 mm and 15 mm, 12.5 mm and 17.5 mm, between 15 mm and 20 mm.For example, the outer diameter D4 is equal to the outer diameters D2 ofthe locking members 322 on the core 306. The outer diameter D4 is 1 to 5mm greater than the diameter D1 of the shaft 314, e.g., 1 to 3 mm, 2 to4 mm, or 3 to 5 mm greater than the diameter D1 of the shaft 314.

While the support structure 304 supports the sheath 302 and isinterlocked with the sheath 302 at one or more portions of the sheath302, the sheath 302 is radially unsupported and circumferentiallyunsupported along some portions of the sheath 302. Referring back toFIG. 3D, the support members 326 a, 326 b and the central portion 320 ofthe core 306 form a support system that radially support the sheath 302at three distinct portions 344 a, 344 b, 344 c. The inner surface of thesheath 302 is directly radially or transversally supported at thesupported portions 344 a, 344 b, 344 c. For example, the supportedportion 344 a and the support member 326 a form a cylindrical joint inwhich relative sliding along the longitudinal axis 312 and relativerotation about the longitudinal axis 312 are allowed while other modesof motion are inhibited. The supported portion 344 c and the supportmember 326 b also form a cylindrical joint. Relative motion along orabout the longitudinal axis 312 is accompanied with friction between thesupported portions 344 a, 344 b and the support members 326 a, 326 b.The supported portion 344 b and the central portion 320 of the core 306form a rigid joint in which relative translation and relative rotationbetween the supported portion 344 b and the central portion 320 areinhibited.

The sheath 302 is unsupported at portions 346 a, 346 b, 346 c, 346 d.The unsupported portion 346 a corresponds to the portion of the sheath302 between a first end portion 348 a of the sheath 302 and thesupported portion 344 a, e.g., between the first end portion 348 a ofthe sheath 302 and the support member 326 a. The unsupported portion 346b corresponds to the portion of the sheath 302 between the supportedportion 344 a and the supported portion 344 b, e.g., between the supportmember 326 a and the center 325 of the roller 300. The unsupportedportion 346 c corresponds to the portion of the sheath 302 between thesupported portion 344 b and the supported portion 344 c, e.g., betweenthe center 325 of the roller 300 and the support member 326 b. Theunsupported portion 346 d corresponds to the portion of the sheath 302between the supported portion 344 b and a second end portion 348 b ofthe sheath 302, e.g., between the support member 326 b and the secondend portion 348 b of the sheath 302.

The unsupported portions 346 b, 346 c overlie internal air gaps 352 a,352 b defined by the sheath 302 and the support structure 304. The airgap 352 a of the roller 300 corresponds to a space between the outersurface of the core 306, the support member 326 a, and the inner surfaceof the sheath 302. The air gap 352 b corresponds to a space between theouter surface of the core 306, the support member 326 b, and the innersurface of the sheath 302. The air gaps 352 a, 352 b extendlongitudinally along entire lengths of the unsupported portions 346 b,346 c from the central portion 320 of the core 306 to the supportmembers 326 a, 326 b. The air gaps 352 a, 352 b separate the supportstructure 304 from the sheath 302 along the unsupported portions 346 b,346 c. These air gaps 352 a, 352 b enable the sheath 302 to deforminwardly toward the longitudinal axis 312 into the air gaps 352 a, 352b, e.g., due to contact with debris on the floor surface during acleaning operation.

The supported portions 344 a, 344 b, 344 c deform relatively less thanthe unsupported portions 346 a, 346 b, 346 c, 346 d when the sheath 302of the roller 300 contacts objects, such as the floor surface 10 anddebris on the floor surface 10. In some cases, the unsupported portions346 a, 346 b, 346 c, 346 d of the sheath 302 deflect in response tocontact with the floor surface 10, while the supported portions 344 a,344 b, 344 c are radially compressed with little inward deflectioncompared to the inward deflection of the unsupported portions 346 a, 346b, 346 c, 346 d. The amount of radial compression of the supportedportions 344 a, 344 b, 344 c is less than the amount of radialdeflection of the unsupported portions 346 a, 346 b, 346 c, 346 dbecause the supported portions 344 a, 344 b, 344 c are supported bymaterial that extends radially toward the shaft portion 314, e.g.,supported by the support members 326 a, 326 b and the central portion320 of the core 306.

The unsupported portions 346 a, 346 d have lengths L5 between 15 and 25mm, e.g., between 15 mm and 20 mm, 17.5 mm and 22.5 mm, or 20 mm and 25mm. Each of the lengths L5 is 5% to 25% of the length L1 of the roller300, e.g., between 5% and 15%, 10% and 20%, or 15% and 25% of the lengthL1 of the roller 300.

In some implementations, the sheath 302 contacts the core 306 only atthe center 325 of the roller 300. Lengths L6, L7 corresponds to lengthsof the air gaps 352 a, 352 b, e.g., the distance between the center 325of the roller 300 and either of the support members 326 a, 326 b, thedistance between the first longitudinal ends 324 a of the locking member324 and the first support member 326 a, or the distance between thesecond longitudinal ends 324 b of the locking member and the secondsupport member 326 b. The lengths L6, L7 are between 80 mm and 100 mm,e.g., between 80 mm and 90 mm, 85 mm and 95 mm, or 90 mm and 100 mm. Forexample, the lengths L6, L7 are equal to the distances L4 between eitherof the support members 326 a, 326 b and the center 325. Each of thelengths L6, L7 is between 25% and 45% of the length L1 of the roller300, e.g., between 25% and 35%, 30% and 40%, or 35% and 45% of thelength L1 of the roller 300. Each of the lengths L6, L7 is at least 25%of the length L1 of the roller 300, e.g., at least 30%, at least 35%, atleast 40% or at least 45% of the length L1 of the roller 300. Thecombined value of the lengths L6, L7 is at least 50% of the length L1 ofthe roller 300, e.g., at least 60%, at least 70%, at least 80%, or atleast 90% of the length L1 of the roller 300. In some implementations,the sheath 302 contacts the core 306 only at a point, e.g., at thecenter 325 of the roller 300, while in other implementations, the sheath302 and the core 306 contact one another along a line extending along25% to 100% of a length of the central portion 320 of the core 306.

As described herein, in addition to providing radial support to thesheath 302, the core 306 also provides circumferential support, inparticular, by circumferentially abutting the sheath 302 with thecentral portion 320. For example, the circumferential support providedby the central portion 320 enables rotation of the core 306 to causerotation of the sheath 302. In addition, when a torsional force isapplied to the sheath 302 due to contact with an object, the sheath 302substantially does not rotate relative to the core 306 at the centralportion 320 of the core 306 because the sheath 302 is rotationally fixedto the core 306 at the central portion 320. In some implementations, theonly location that the sheath 302 is rotationally supported is at thesupported portion 344 b of the sheath 302. In this regard, otherportions of the sheath 302 can rotationally deform relative to thesupported portion 344 b and thereby rotate relative to the core 306.

In some implementations, the support members 326 a, 326 b providecircumferential support by generating a frictional reaction forcebetween the support members 326 a, 326 b and the sheath 302. When atorque is applied to the core 306 and hence the support members 326 a,326 b rotationally coupled to the core 306, a portion of the torque maytransfer to the sheath 302. Similarly, when a torque is applied to thesheath 302, a portion of the torque may transfer to the core 306.However, during a cleaning operation, the sheath 302 will generallyexperience torques due to contact between the sheath 302 and an objectthat will be sufficiently great to cause relative rotation betweenportions of the sheath 302 and the support members 326 a, 326 b, e.g.,between the support members 326 a, 326 b and portions of the sheath 302overlying the support members 326 a, 326 b. This allowed relativerotation can improve debris pickup by the sheath 302.

The sheath 302 extends beyond the core 304 of the support structure 303along the longitudinal axis 312 of the roller 300, in particular, beyondthe first end portion 308 and the second end portion 310 of the core306. The shell 350 of the sheath 302 includes a first half 354 and asecond half 356. The first half 354 corresponds to the portion of theshell 350 on one side of a central plane 327 passing through the center325 of the roller 300 and perpendicular to the longitudinal axis 312 ofthe roller 300. The second half 356 corresponds to the other portion ofthe shell 350 on the other side of a central plane 327. The centralplane 327 is, for example, a bisecting plane that divides the roller 300into two symmetric halves. The shell 350 has a wall thickness between0.5 mm and 3 mm, e.g., 0.5 mm to 1.5 mm, 1 mm to 2 mm, 1.5 mm to 2.5 mm,or 2 mm to 3 mm.

Referring to FIG. 3D, the roller 300 includes a first collection well358 and a second collection well 360. The collection wells 358, 360correspond to volumes on ends of the roller 300 where filament debrisengaged by the roller 300 tend to collect. In particular, as the roller300 engages filament debris on the floor surface 10 during a cleaningoperation, the filament debris moves over the end portions 348 a, 348 bof the sheath 302, wraps around the core 306, and then collects withinthe collection wells 358, 360. The filament debris wraps around thefirst and second end portions 308, 310 of the core 306 and can be easilyremoved from the elongate the first and second end portions 308, 310 bythe user. In this regard, the first and second end portions 308, 310 arepositioned within the collection wells 358, 360. The collection wells358, 360 are defined by the sheath 302 and the support members 326 a,326 b. The collection wells 358, 360 are defined by the unsupportedportions 346 a, 346 d of the sheath 302 that extend beyond the supportmembers 326 a, 326 b.

The first collection well 358 is positioned within the first half 354 ofthe shell 350. The first collection well 358 is, for example, defined bythe support member 326 a, the unsupported portion 346 a of the sheath302, and the portion of the core 306 extending through the unsupportedportion 346 a of the sheath 302. The length L5 of the unsupportedportion 346 a of the sheath 302 defines the length of the firstcollection well 358.

The second collection well 360 is positioned within the second half 356of the shell 350. The second collection well 360 is, for example,defined by the support member 326 b, the unsupported portion 346 b ofthe sheath 302, and the portion of the core 306 extending through theunsupported portion 346 b of the sheath 302. The length L5 of theunsupported portion 346 d of the sheath 302 defines the length of thesecond collection well 360.

Referring to FIG. 5A, in some implementations, the sheath 302 of theroller 300 is a monolithic component including the shell 350 andcantilevered vanes extending substantially radially from the outersurface of the shell 350. Each vane has one end fixed to the outersurface of the shell 350 and another end that is free. The height ofeach vane is defined as the distance from the fixed end at the shell350, e.g., the point of attachment to the shell 350, to the free end.The free end sweeps an outer circumference of the sheath 302 duringrotation of the roller 300. The outer circumference is consistent alongthe length of the roller 300. Because the radius from the longitudinalaxis 312 to the outer surface of the shell 350 decreases from the endportions 348 a, 348 b of the sheath 302 to the center 325, the height ofeach vane increases from the end portions 348 a, 348 b of the sheath 302to the center 325 so that the outer circumference of the roller 300 isconsistent across the length of the roller 300. In some implementations,the vanes are chevron shaped such that each of the two legs of each vanestarts at opposing end portions 348 a, 348 b of the sheath 302, and thetwo legs meet at an angle at the center 325 of the roller 300 to form a“V” shape. The tip of the V precedes the legs in the direction ofrotation.

FIGS. 5A and 5B depict one example of the sheath 302 including one ormore vanes on an outer surface of the shell 350. While a single vane 362is described herein, the roller 300 includes multiple vanes in someimplementations, with each of the multiple vanes being similar to thevane 362 but arranged at different locations along the outer surface ofthe shell 350. For example, the sheath 302 includes 4 to 12 vanes, e.g.,4 to 8 vanes, 6 to 10 vanes, or 8 to 12 vanes. The vane 362 is adeflectable portion of the sheath 302 that, in some cases, engages withthe floor surface 10 when the roller 300 is rotated during a cleaningoperation. The vane 362 extends along outer surfaces of the first half354 and the second half 356 of the shell 350. The vane 362 extendsradially outwardly from the sheath 302 and away from the longitudinalaxis 312 of the roller 300. The vane 362 deflects when it contacts thefloor surface 10 as the roller 300 rotates.

Referring to FIG. 5E, the vane 362 extends from a first end 362 a fixedto the shell 350 and a second free end 362 b. A height of the vane 362corresponds to, for example, a height H1 measured from the first end 362a to the second end 362 b, e.g., a height of the vane 362 measured fromthe outer surface of the shell 350. The height H1 of the vane 362proximate the center 325 of the roller 300 is greater than the height H1of the vane 362 proximate the first end portion 348 a and the secondportion 348 b of the sheath 302. The height H1 of the vane 362 proximatethe center of the roller 300 is, in some cases, a maximum height of thevane 362. In some cases, the height H1 of the vane 362 linearlydecreases from the center 325 of the roller 300 toward the first endportion 348 a of the sheath 302 and toward the second end portion 348 bof the sheath 302. In some implementations, the vane 362 is angledrearwardly relative to a direction of rotation 363 of the roller 300such that the vane 362 more readily deflects in response to contact withthe floor surface 10.

Referring to FIG. 5D, the vane 362 follows, for example, a V-shaped path366 along the outer surface of the shell 350. The V-shaped path 366includes a first leg 366 a and a second leg 366 b that extend from thecentral plane 327 toward the first end portion 348 a and the second endportion 348 b of the sheath 302, respectively. The first and second legs366 a, 366 b extend circumferentially along the outer surface of theshell 350, in particular, in the direction of rotation 363 of the roller300. The height H1 of the vane 362 decreases along the first leg 366 aof the path 366 from the central plane 327 toward the first end portion348 a of the sheath 302, and the height H1 of the vane 362 decreasesalong the second leg 366 b of the path 366 from the central plane 327toward the second end portion 348 b of the sheath 302. In some cases,the height of the vanes 362 decreases linearly from the central plane327 toward the second end portion 348 b and decreases linearly from thecentral plane 327 toward the first end portion 348 a.

In some cases, an outer diameter D5 of the sheath 302 corresponds to adistance between free ends 362 b, 364 b of vanes 362, 364 arranged onopposite sides of a plane through the longitudinal axis 312 of theroller 300. The vane 364, having a fixed end 364 a and a free end 364 b,is similar to the vane 362 except that it extends along a different pathalong the outer surface of the shell 350. The outer diameter D5 of thesheath 302 is, in some cases, uniform across the entire length of thesheath 302. In this regard, despite the taper of the halves 354, 356 ofthe shell 350, the outer diameter of the sheath 302 is uniform acrossthe length of the sheath 302 because of the varying height of the vanes362, 364 of the sheath 302.

In some implementations, as shown in FIG. 6, a width or diameter of theroller 300 between the end portion 348 a and the end portion 348 b ofthe sheath 302 corresponds to the diameter D5 of the sheath 302. Thediameter D5 is, in some cases, uniform from the end portion 348 a to theend portion 348 b of the sheath 302. The diameter D5 of the roller 300at different positions along the longitudinal axis 312 of the roller 300between the position of the end portion 348 a and the position of theend portion 348 b is equal. The diameter D5 is between, for example, 20mm and 60 mm, e.g., between 20 mm and 40 mm, 30 mm and 50 mm, 40 mm and60 mm, etc.

Referring to FIG. 5E, the height H1 of the vane 362 is, for example,between 0.5 mm and 25 mm, e.g., between 0.5 and 2 mm, 5 and 15 mm, 5 and20 mm, 5 and 25 mm, etc. The height H1 of the vane 362 at the centralplane 327 is between, for example, 2.5 and 25 mm, e.g., between 2.5 and12.5 mm, 7.5 and 17.5 mm, 12.5 and 25 mm, etc. The height H1 of the vane362 at the end portions 348 a, 348 b of the sheath 302 is between, forexample, 0.5 and 5 mm, e.g., between 0.5 and 1.5 mm, 0.5 and 2.5 mm,etc. The height H1 of the vane 362 at the central plane 327 is, forexample, 1.5 to 50 times greater than the height H1 of the vane 362 atthe end portions 348 a, 348 b of the sheath 302, e.g., 1.5 to 5, 5 to10, 10 to 20, 10 to 50, etc., times greater than the height H1 of thevane 362 at the end portions 348 a, 348 b of the sheath 302. The heightH1 of the vane 362 at the central plane 327, for example, corresponds tothe maximum height of the vane 362, and the height H1 of the vane 362 atthe end portions 348 a, 348 b of the sheath 302 corresponds to theminimum height of the vane 362. In some implementations, the maximumheight of the vane 362 is 5% to 45% of the diameter D5 of the sheath302, e.g., 5% to 15%, 15% to 30%, 30% to 45%, etc., of the diameter D5of the sheath 302.

Referring to FIG. 3D, the shell 350 of the sheath 302 tapers along thelongitudinal axis 312 of the roller 300 toward the center 325, e.g.,toward the central plane 327. Both the first half 354 and the secondhalf 356 of the shell 350 taper along the longitudinal axis 312 towardthe center 325, e.g., toward the central plane 327, over at least aportion of the first half 354 and the second half 356, respectively. Insome implementations, the first half 354 tapers from the first outer endportion 348 a to the center 325, and the second half 356 tapers from thesecond outer end portion 348 b to the center 325. In someimplementations, rather than tapering toward the center 325 along anentire length of the sheath 302, the shell 350 of the sheath 302 taperstoward the center 325 along the unsupported portions 346 b, 346 c anddoes not taper toward the center 325 along the unsupported portions 346a, 346 d.

In this regard, the first half 354 and the second half 356 arefrustoconically shaped. Central axes of the frustocones formed by thefirst half 354, the second half 356 each extends parallel to and throughthe longitudinal axis 312 of the roller 300. Accordingly, the innersurfaces defined by the unsupported portions 346 a, 346 b, 346 c, 346 dare each frustoconically shaped and tapered toward the center 325 of theroller 300. Furthermore, the air gaps 352 a, 352 b are frustoconicallyshaped and tapered toward the center 325 of the roller 300.

An outer diameter D6 of the shell 350 at the central plane 327 is, forexample, less than outer diameters D7, D8 of the shell 350 at the outerend portions 348 a, 348 b of the sheath 302. In some cases, the outerdiameter of the shell 350 linearly decreases toward the center 325.

The diameter of the shell 350 of the sheath 302 may vary at differentpoints along the length of the shell 350. The diameter D6 of the shell350 along the central plane 327 is between, for example, 7 mm and 22 mm,e.g., between 7 and 17 mm, 12 and 22 mm, etc. The diameter D6 of theshell 350 along the central plane 327 is, for example, defined by thedistance between outer surfaces of the shell 350 along the central plane327. The diameters D7, D8 of the shell 350 at the outer end portions 348a, 348 b of the sheath 302 are, for example, between 15 mm and 55 mm,e.g., between 15 and 40 mm, 20 and 45 mm, 30 mm and 55 mm, etc.

The diameter D6 of the shell 350 is, for example, between 10% and 50% ofthe diameter D8 of the sheath 302, e.g., between 10% and 20%, 15% and25%, 30% and 50%, etc., of the diameter D8. The diameters D6, D7 of theshell 350 is, for example, between 80% and 95% of the diameter D8 of thesheath 302, e.g., between 80% and 90%, 85% and 95%, 90% and 95%, etc.,of the diameter D8 of the sheath 302.

In some implementations, the diameter D6 corresponds to the minimumdiameter of the shell 350 along the length of the shell 350, and thediameters D7, D8 correspond to the maximum diameter of the shell 350along the length of the shell 350. In the example depicted in FIG. 1A,the length S2 of the separation 108 is defined by the maximum diametersof the shells of the rollers 104 a, 104 b. The length S3 of theseparation 108 is defined by the minimum diameters of the shells of therollers 104 a, 104 b.

The diameter of the shell 350 also varies linearly along the length ofthe shell 350 in some examples. From the minimum diameter to the maximumdiameter along the length of the shell 350, the diameter of the shell350 increases with a slope M1. The slope M1 is between, for example,0.01 to 0.4 mm/mm, e.g., between 0.01 to 0.3 mm/mm, 0.05 mm to 0.35mm/mm, etc. The angle between the slope M1 and the longitudinal axis 312is between, for example, 0.5 degrees and 20 degrees, e.g., between 1 and10 degrees, 5 and 20 degrees, 5 and 15 degrees, 10 and 20 degrees, etc.In particular, the slope M1 corresponds to the slope of the frustoconesdefined by the first and second halves 354, 356 of the shell 350.

When the roller 300 is paired with another roller, e.g., the roller 104b, the outer surface of the shell 350 of the roller 300 and the outersurface of the shell 350 of the other roller defines a separationtherebetween, e.g., the separation 108 described herein. The rollersdefine an air opening therebetween, e.g., the air opening 109 describedherein. Because of the taper of the first and second halves 354, 356 ofthe shell 350, the separation increases in size toward the center 325 ofthe roller 300. The frustoconical shape of the halves 354, 356facilitate movement of filament debris picked up by the roller 300toward the end portions 348 a, 348 b of the sheath 302. The filamentdebris can then be collected into the collection wells 358, 360 suchthat a user can easily remove the filament debris from the roller 300.In some examples, the user dismounts the roller 300 from the robot toenable the filament debris collected within the collection wells 358,360 to be removed.

In some cases, the air opening varies in size because of the taper ofthe first and second halves 354, 356 of the shell 350. In particular,the width of the air opening depends on whether the vanes 362, 364 ofthe roller 300 face the vanes of the other roller. While the width ofthe air opening between the sheath 302 of the roller 300 and the sheathof the other roller varies along the longitudinal axis 312 of the roller300, the outer circumferences of the rollers are consistent. Asdescribed with respect to the roller 300, the free ends 362 b, 364 b ofthe vanes 362, 364 define the outer circumference of the roller 300.Similarly, free ends of the vanes of the other roller define the outercircumference of the other roller. If the vanes 362, 364 face the vanesof the other roller, the width of the air opening corresponds to aminimum width between the roller 300 and the other roller, e.g., adistance between the outer circumference of the shell 350 of the roller300 and the outer circumference of the shell of the other roller. If thevanes 362, 364 of the roller and the vanes of the other roller arepositioned such that the width of the air opening is defined by thedistance between the shells of the rollers and corresponds to a maximumwidth between the rollers, e.g., between the free ends 362 b, 362 b ofthe vanes 362, 364 of the roller 300 and the free ends of the vanes ofthe other roller.

Alternative Implementations

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made.

While the robot 102 is described as having a rectangular shaped frontportion 202 a and a semicircular shaped rear portion 202 b, in someimplementations, an outer perimeter of the robot 102 defines anotherappropriate shape. For example, in some cases, the body 200 of the robot102 has a substantially circular shape. Alternatively, the body 200 ofthe robot 102 has a substantially rectangular shape, a substantiallysquare shape, a substantially ellipsoidal shape, or a substantiallyReuleaux polygonal shape.

While some of the foregoing examples are described with respect to asingle roller 300 or the roller 104 a, the roller 300 is similar to thefront roller 104 b with the exception that the arrangement of vanes 362of the roller 300 differ from the arrangement of the vanes 224 b of thefront roller 104 b, as described herein. In particular, because theroller 104 b is a front roller and the roller 104 a is a rear roller,the V-shaped path for a vane 224 a of the roller 104 a is symmetric tothe V-shaped path for a vane 224 b of the roller 104 b, e.g., about avertical plane equidistant to the longitudinal axes 126 a, 126 b of therollers 104 a, 104 b. The legs for the V-shaped path for the vane 224 bextend in the counterclockwise direction 130 b along the outer surfaceof the shell 222 b of the roller 104 b, while the legs for the V-shapedpath for the vane 224 a extend in the clockwise direction 130 a alongthe outer surface of the shell 222 a of the roller 104 a.

While the supported portion 344 b is described as being positioned atthe center 325 of the roller 300, in some implementations, the centralportion 320 of the core 306 supports the sheath 302 at a location offsetfrom the center 325 of the roller 300, e.g., offset from the center 325by 1 cm to 5 cm. In some implementations, the support members 326 a, 326b are symmetrically arranged around the central plane 327 and areequidistant from the center 325 of the roller 300. In otherimplementations, one of the support members 326 a, 326 b is positionedat a distance further from the center 325 than a distance between theother of the support members 326 a, 326 b and the center 325.

While filament debris is described as being collected in the collectionwell 358, in some implementations, the filament debris is collected onthe mounting device 316. For example, the mounting device 316 includes arecessed ring-shaped portion (with a center coincident with thelongitudinal axis 312) where the filament debris is collected.

The support members 326 a, 326 b have circular outer perimeters.Geometry of interior portions of the support members 326 a, 326 b, e.g.,portions within the circular outer perimeters, can vary betweenimplementations. FIGS. 7A and 7B illustrate an example of a supportmember 700 that can be used as a support member for a cleaning roller,e.g., the roller 300. The support member 700 includes an inner ring 702,an outer ring 704, and elongate members 706 extending between the innerring 702 and the outer ring 704. The inner ring 702, when the supportmember 700 is mounted to the core 306 of the roller 300, is coupled tothe core 306. The inner ring 702 abuts the locking members 336, 338 (ifthe support member 700 corresponds to the first support member 326 a) orabuts the locking members 340, 342 (if the support member 700corresponds to the second support member 326 b). The outer ring 704contacts the inner surface of the sheath 302 to provide radial supportto the sheath 302.

The elongate members 706 extend along and parallel to radial axesextending outwardly from a center of the support member 700. Theelongate members 706 are structural support members for the outer ring704 to provide radial support to the sheath 302. Adjacent elongatemembers 706 define gaps 708, thereby reducing the amount of materialrequired to form the support member 700. The elongate members 706include protruding portions 710 to increase the stiffness of theelongate members 706 and thereby provide more radial support for thesheath 302 of the roller 300.

FIGS. 8A and 8B illustrate another example of a support member 800 thatcan be used as a support member for the roller 300. The support member800 includes an inner ring 802 and an outer ring 804 similar to theinner ring 702 and the outer ring 704. The support member 800 differsfrom the support member 700 in that elongate members 806 of the supportmember 800 are angled relative to radially extending axes of the supportmember 800. In particular, the elongate members 806 and a radial axis(e.g., an axis perpendicular to a central axis through the center of thesupport member 800) form a non-zero angle. In some implementations, thisnon-zero angle is between 15 and 80 degrees, e.g., between 15 and 30degrees, between 30 and 45 degrees, between 45 and 60 degrees, between60 and 80 degrees, between 30 and 80 degrees, or between 50 and 80degrees. The elongate members 806, when the support member 800 ismounted to the core 306, are angled away from the direction of rotation363 (shown in FIG. 5D), e.g., extend outward from the inner ring 702 ata non-perpendicular angle relative to the direction of rotation 363. Theelongate members 806 are angled such that torsion applied to the outerring 704 during rotation of the roller 300 tends to cause the elongatemembers 806 to extend.

FIGS. 9A and 9B illustrate another example of a support member 900 thatcan be used as a support member for the roller 300. The support member900 differs from the support members 700 and 800 in that the supportmember 900 includes an inner ring 902 and an outer ring 904 similar tothe inner rings 702, 802 and the outer rings 804, 904, with the innerring 902 abutting the locking members of the core 306, and the outerring 904 radially inwardly supporting the sheath 302. As shown in FIG.9B, the support member 900 includes a support ring 906 that extendsradially outward from the inner ring 902 to the outer ring 904 at anon-perpendicular angle to the longitudinal axis 312. The support ring906 is a solid continuous ring of material connecting the inner ring 902and the outer ring 904. The angle A1 between the support ring 906 andthe longitudinal axis 312 is between 45 and 60 degrees, e.g., between 45and 55 degrees or 50 and 60 degrees.

While the support members 326 a, 326 b are described as separate fromthe core 306, in some implementations, the support members 326 a, 326 band the core 306 are integrally formed with respect to one another. Atleast the support members 326 a, 326 b and the core 306 form amonolithic portion of the support structure 304.

While the support members 326 a, 326 b are described as maintaining thecircular cross-section of the shell 350 of the sheath 302 at locationsat which the support members 326 a, 326 b support the shell 350, in someimplementations, the support members 326 a, 326 b are also deformable.In some implementations, the support members 326 a, 326 b are deformablesuch that their outer surfaces 328 a, 328 b become non-circular inresponse to deformation. The support members 326 a, 326 b deform inresponse to deformation of the sheath 302. In this regard, while thesupported portions 344 a, 344 c deform relatively less than theunsupported portions 346 a-346 d, the supported portions 344 a, 344 care still capable of being deformed in response to contact with objectssuch as debris or the floor surface. As a result, the shell 350 of thesheath 302 can be deformed into non-circular cross-sections at thesupported portions 344 a, 344 c.

While the roller 300 is described as having two support members 326 a,326 b, in some implementations, the roller 300 includes 0, 1, or 3 ormore support members. If the roller 300 includes 3 or more supportmembers, the support member or support members in addition to thesupport members 326 a, 326 b can be positioned between the supportmembers 326 a, 326 b and the central portion 320 of the core 306. Insome implementations, the support members are uniformly spaced along thelongitudinal axis 312 of the roller 300.

The sheath 302 is described as having vanes, e.g., the vanes 362, 364,extending along outer surfaces of the shell 350. In someimplementations, as shown in FIGS. 10A and 10B, the sheath 302 furtherincludes nubs 1000 extending radially outward from the outer surfaces ofthe shell 350. The nubs 1000 protrude radially outwardly from the outersurface of the shell 350 and are spaced apart from one another along theouter surface of the shell 350. A first portion 1002 a of the nubs 1000extends longitudinally from the first end portion 348 a of the sheath302 toward the center 325 of the roller 300 along a length L8. A secondportion 1002 b of the nubs 1000 extends longitudinally from the secondend portion 348 b of the sheath 302 toward the center 325 of the roller300 along a length L9. The first portion 1002 a of the nubs 1000 and thesecond portion 1002 b of the nubs 1000 do not extend across an entirelength L1 of the roller 300. The lengths L8, L9 are each 50 mm to 90 mm,e.g., 50 to 70 mm, 60 to 80 mm, or 70 to 90 mm. The lengths L8, L9 are10% to 40% of the length L1 of the roller 300, e.g., between 10% and20%, between 15% and 25%, between 15% and 35%, between 20% and 30%,between 25% and 35%, or between 30% and 40% of the length L1 of theroller 300.

The first portion 1002 a of the nubs 1000 extends along a portion 1004 aof a path 1004 circumferentially offset from the path 366 for the vane362, and the second portion 1002 b of the nubs 1000 extends along aportion 1004 b of the path 1004. The path 1004 is a V-shaped path, andthe portions 1004 a, 1004 b corresponds to portions of legs of the path1004. In this regard, the path 1004 extends both circumferentially andlongitudinally along the outer surface of the shell 350. The nubs 1000each has a length of 2 to 5 mm, e.g., 2 to 3 mm, 3 to 4 mm, or 4 to 5mm. The spacing between adjacent nubs 1000 along the path 1004 has alength of 1 to 4 mm, e.g., 1 to 2 mm, 2 to 3 mm, or 3 to 4 mm.

As described herein, the height H1 of the vane 362 relative to thelongitudinal axis 312 is uniform across a length of the roller 300. Insome implementations, referring to FIG. 10C, heights H2 of the nubs 1000relative to the shell 350 of the sheath 302 are uniform along theportions 1004 a, 1004 b of the path 1004. The height H1 of the vane 362is 0.5 to 1.5 mm greater than the heights H2 of the nubs 1000, e.g., 0.5to 1 mm, 0.75 to 1.25 mm, or 1 to 1.5 mm greater than the heights H2 ofthe nubs 1000.

In some implementations, paths for the vanes are positioned betweenadjacent paths for nubs, and paths for nubs are positioned betweenadjacent paths for vanes. In this regard, the paths for nubs and thepaths for vanes are alternately arranged around the outer surface of theshell 350. For example, the first portion 1002 a of the nubs 1000 andthe second portion 1002 b of nubs 1000 are positioned between a firstvane 1006, e.g., the vane 362, and a second vane 1008. The nubs 1000form a first set of nubs 1000 extending along the portions 1004 a, 1004b of the path 1004, and the first and second vanes 1006, 1008 extendalong V-shaped paths 1010, 1012, respectively. The path 1004 ispositioned circumferentially between the paths 1010, 1012. Nubs 1014form a second set of nubs 1014 that extends along portions 1016 a, 1016b of a path 1016. The path 1010 for the first vane 1006 is positionedcircumferentially between the paths 1004, 1016 for the first and secondset of nubs 1000, 1014.

In some implementations, the roller 104 a and the roller 104 b havedifferent lengths. The roller 104 b is, for example, shorter than theroller 104 a. The length of the roller 104 b is, for example, 50% to 90%the length of the roller 104 a, e.g., 50% to 70%, 60% to 80%, 70% to 90%of the length of the roller 104 a. If the lengths of the rollers 104 a,104 b are different, the rollers 104 a, 104 b are, in some cases,configured such that the minimum diameter of the shells 222 a, 222 b ofthe rollers 104 a, 104 b are along the same plane perpendicular to boththe longitudinal axes 126 a, 126 b of the rollers 104 a, 104 b. As aresult, the separation between the shells 222 a, 222 b is defined by theshells 222 a, 222 b at this plane.

Accordingly, other implementations are within the scope of the claims.

1-20. (canceled)
 21. A cleaning roller mountable to a cleaning robot,the cleaning roller comprising: a sheath comprising a shell, an outerdiameter of the shell tapering from a first end portion of the sheathand a second end portion of the sheath toward a center of the cleaningroller; and a core extending from a first end portion of the core to asecond end portion of the core along an axis of rotation of the cleaningroller, the cleaning roller mountable to the cleaning robot for rotatingabout the axis of rotation, wherein an inner surface of the shell and anouter surface of the core form an air gap therebetween, the air gapextending, from a portion of the core between the first end portion ofthe core and the second end portion of the core, longitudinally alongthe axis of rotation toward the first end portion or the second endportion of the core.
 22. The cleaning roller of claim 21, wherein theportion of the core is rotationally coupled with the sheath.
 23. Thecleaning roller of claim 21, wherein the portion of the core is acentral portion of the core.
 24. The cleaning roller of claim 21,wherein: the portion of the core comprises one or more locking membersextending radially outward from a shaft portion of the core, and thesheath comprises one or more locking members extending radially inwardfrom an inner surface of the shell, the one or more locking members ofthe sheath abutting the one or more locking members of the portion ofthe core in a first longitudinal direction and a second longitudinaldirection.
 25. The cleaning roller of claim 21, wherein the portion ofthe core is interlocked with the sheath such that at least a portion ofthe core is rotationally coupled with the sheath and such that relativetranslation of the sheath and the core along the axis of rotation isinhibited.
 26. The cleaning roller of claim 21, wherein: the portion ofthe core comprises one or more locking members extending radiallyoutward from a shaft portion of the core, and the sheath comprises oneor more locking members extending radially inward from an inner surfaceof the shell, the one or more locking members of the sheath abutting theone or more locking members of the portion of the core in a direction ofrotation of the cleaning roller about the axis of rotation.
 27. Thecleaning roller of claim 21, wherein the air gap has a length at least25% of a length of the cleaning roller.
 28. The cleaning roller of claim21, wherein the sheath is configured to deform inwardly into the air gaptoward the axis of rotation of the cleaning roller.
 29. The cleaningroller of claim 21, wherein the sheath comprises: a first unsupportedportion that is unsupported by the core, and a second unsupportedportion that is unsupported by the core, wherein the first unsupportedportion of the sheath is longitudinally positioned between the first endportion of the core and the portion of the core, and wherein the secondunsupported portion of the sheath is longitudinally positioned betweenthe second end portion of the core and the portion of the core.
 30. Thecleaning roller of claim 21, further comprising: a first support memberproximate the first end portion of the core and extending radiallyoutward from the outer surface of the core toward the inner surface ofthe shell, and a second support member proximate the second end portionof the core and extending radially outward from the outer surface of thecore toward the inner surface of the shell, wherein the core extendsalong the axis of rotation through centers of the first and secondsupport members.
 31. The cleaning roller of claim 21, wherein the airgap tapers away from the first end portion or the second end portion ofthe core.
 32. The cleaning roller of claim 21, further comprising acollection well between the air gap and the first end portion of thecore or the second end portion of the core, the collection well having alength between 5% and 25% of an overall length of the cleaning roller,and the air gap having a length between 25% and 45% of the overalllength of the cleaning roller.
 33. The cleaning roller of claim 32,wherein: the air gap is a first air gap extending between the first endportion of the core and the portion of the core, and the inner surfaceof the shell and the outer surface of the core form a second air gaptherebetween, and the cleaning roller further comprises a secondcollection well between the second air gap and the second end portion ofthe core, the second collection well having a length between 5% and 25%of the overall length of the cleaning roller, and the second air gaphaving a length between 25% and 45% of the overall length of thecleaning roller.
 34. The cleaning roller of claim 21, wherein the sheathcontacts the core along only the portion of the core.
 35. The cleaningroller of claim 21, wherein the sheath comprises a plurality of vanesextending outwardly from the shell of the sheath and defining an outerdiameter of the cleaning roller.
 36. The cleaning roller of claim 21,wherein the first and second end portions of the core are mountable tothe cleaning robot for rotating about the axis of rotation.
 37. Anautonomous cleaning robot comprising: a drive configured to move theautonomous cleaning robot across a floor surface; a cleaning assemblycomprising a first cleaning roller, the first cleaning roller comprisinga sheath comprising a shell, an outer diameter of the shell taperingfrom a first end portion of the sheath and a second end portion of thesheath toward a center of the first cleaning roller; and a coreextending from a first end portion of the core to a second end portionof the core along an axis of rotation of the first cleaning roller, thefirst cleaning roller mountable to the autonomous cleaning robot forrotating about the axis of rotation, wherein an inner surface of theshell and an outer surface of the core form an air gap therebetween, theair gap extending, from a portion of the core between the first endportion of the core and the second end portion of the core,longitudinally along the axis of rotation toward the first end portionor the second end portion of the core; and a second cleaning rollerrotatably mounted to the autonomous cleaning robot, the second cleaningroller comprising a sheath comprising a shell, the shell of the secondcleaning roller and the shell of the first cleaning roller defining aseparation therebetween that varies in width along lengths of the firstand second cleaning rollers.
 38. The autonomous cleaning robot of claim37, wherein the portion of the core is rotationally coupled with thesheath.
 39. The autonomous cleaning robot of claim 37, wherein theportion of the core is a central portion of the core.
 40. The autonomouscleaning robot of claim 37, wherein: the portion of the core comprisesone or more locking members extending radially outward from a shaftportion of the core, and the sheath comprises one or more lockingmembers extending radially inward from an inner surface of the shell,the one or more locking members of the sheath abutting the one or morelocking members of the portion of the core in a first longitudinaldirection and a second longitudinal direction.